Machines today are designed with corresponding virtual representations. The physical and digital counterparts exchange data, which is constantly captured by sensors. This way, companies can detect faults earlier in the development phase—and even monitor machinery and components after distribution.

A perfect look-alike, just in case

Greater product diversity, higher quality and lower production costs: Digital Twins are revolutionizing how industry works. Virtual twins accompany a physical product from the initial conceptualization and the design process right through production and updates - helping digital machine construction run better.

3D models instead of prototypes

Digital Twins are digital representations of physical machines. In industry, they are used to optimize product design and ensure error-free operation. They are formed on the basis of a high-precision 3D CAD model that has been assigned all the properties and functions of the planned product - from its materials and sensoring systems to the movement and dynamics of the real machine. This is an important step towards identifying malfunctions early and resolving them before the start of production - and eliminating the need for development of a costly prototype.

Constant exchange of data

The twins are constantly in connection with one another - even after production and sale of the physical product. The real machine is outfitted with sensors that send status data to its virtual reproduction on a constant basis. A requirement management system functions as a digital requirements library, gathering the incoming data and comparing it against the specifications by which the product was created.

If a discrepancy is detected, then engineers can work on potential solutions directly on the digital twin - after which the real machine can then be updated to resolve the problem as quickly as possibly.

IT security for digital twins

To ensure the security of the Digital Twins, a variety of enhanced security measures from the IT realm are needed in industry. Digital industry systems are an especially common target for malicious software, spread through the internet, corporate intranets or external hardware. The concept of "industrial security" is thus not just focused on physical securing of devices through alarm systems and access codes, but also the use of firewalls in corporate networks and walling off of external electronic interfaces. To protect industrial systems against cyber-attacks, manufacturers such as Siemens and Genua Solutions offer solutions to be deployed at all levels to ensure not only system and network security, but also system integrity.

A sixteenth century woodcut illustrating a statement from an Alexandrian manuscript of the first century AD, stating that if a bull dismounts from the right side of a cow conception will result in a bull calf, whilst descending from the left side will result in a heifer calf. Redrawn by A.J. Lee, adapted from reference [
25
].

A sixteenth century woodcut illustrating a statement from an Alexandrian manuscript of the first century AD, stating that if a bull dismounts from the right side of a cow conception will result in a bull calf, whilst descending from the left side will result in a heifer calf. Redrawn by A.J. Lee, adapted from reference [25].

Throughout most of history, any theories about sex determination had to be formulated in the absence of knowledge of the component parts: eggs and sperm cells. The problem with cells is that they are extremely small and require compound microscopes and specialized techniques to observe them, which became available only in the seventeenth century. The Dutch scientist of the seventeenth century, Antonie van Leeuwenhoek, examined semen from men and dogs, and found it to be populated by a multitude of tiny, eel‐like, little animals. He described his discovery of the spermatic animalcules in a letter to the Royal Society in London in 1676. But where did they come from, and what was their function? The animalcules became a subject of controversy, which lasted for more than a century and a half.

van Leeuwenhoek thought that the animalcules provided the substance of the embryo, while the egg provided the nourishment; but this seemed to run counter to the view that all living things originate from an egg. This latter view was popularized by the seventeenth century English physician William Harvey, famed for his discovery of the blood circulation, who was also a pioneer in the study of reproduction. Although Harvey failed to detect any connection between the ovary and the product of reproduction, he maintained in his book
Exercitationes de Generatione Anmalium
that “all animals whatsoever, even viviparous ones, nay man himself, are all engendered from an egg”. This publication contained a frontispiece of Jupiter holding an egg, from which all manner of animals emerged: on its shell, the words
ex ovo omnia
were engraved and subsequently much misquoted. Although the meaning of ‘egg’ then was not exactly the same as it is today, and despite the absence of evidence of any connection between ‘egg’ and embryo, it served to popularize an important idea that eventually proved its worth.

More information about the mammalian egg was provided by the Dutch physician and anatomist, Reinier de Graaf, who dissected female rabbits at various intervals after mating, and partly succeeded in tracing the ‘eggs’ from the ovary, through the oviduct, to the uterus. His publication on the female organs of generation appeared in 1672. Although de Graaf was aware that the egg, or ovum, in the oviduct was smaller than the ovarian follicle that now bears his name, he did not see the egg himself; but his conclusion that mammalian eggs and ovaries are directly comparable to those of birds has withstood the test of time. It also encouraged the seventeenth century idea that embryos are formed from eggs rather than spermatic animalcules. Indeed, it took another century and a half until Russian naturalist Carl von Baer described and illustrated the mammalian egg inside the Graafian follicle; but he regarded the spermatic animalcules as parasites, and perpetuated this idea by naming them ‘spermatozoa’. The riddle of the spermatozoon was eventually solved by the nineteenth century Swiss anatomist Albert von Kölliker, who concluded that spermatozoa are products of the testes that need to come into contact with the egg to produce an embryo (
Sidebar A
).